Interaction between comminution phenomena and chemical reactions during fluidized bed desulphurization with limestone

Comminution phenomena occurring during calcination and sulphation of an Italian limestone under conditions typical of atmospheric bubbling fluidized bed combustion have been investigated in a bench scale apparatus. A coherent framework of sorbent comminution phenomena is proposed. This includes different types of fragmentation, resulting in the generation of coarse fragments, as well as attrition by abrasion, responsible for the generation of elutriable particulates. The main concern of the study is to characterize the interaction between different sorbent comminution processes and the parallel occurrence of reactions. Experimental results suggest that fragmentation is negligible under the experimental conditions investigated. Attrition by abrasion is appreciable and turns out to be strongly dependent on sorbent conversion degree.